US6567648B1 - System combining radio frequency transmitter and receiver using circulator and method for canceling transmission signal thereof - Google Patents

System combining radio frequency transmitter and receiver using circulator and method for canceling transmission signal thereof Download PDF

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US6567648B1
US6567648B1 US09/656,945 US65694500A US6567648B1 US 6567648 B1 US6567648 B1 US 6567648B1 US 65694500 A US65694500 A US 65694500A US 6567648 B1 US6567648 B1 US 6567648B1
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signal
transmission
transmission signal
reception
transmitter
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Dal Ahn
Jun Seok Park
Jong Chul Park
Chul Sang Yoon
Won Jun Kwak
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Telwave Inc
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Telwave Inc
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Assigned to TELWAVE INC., AHN, DAL reassignment TELWAVE INC. ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: YOON, CHUL SANG, AHN, DAL, KWAK, WON JUN, PARK, JONG CHUL, PARK, JUN SEOK
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40—Circuits
    • H04B1/44—Transmit/receive switching
    • H04B1/48—Transmit/receive switching in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/38—Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving
    • H04B1/40—Circuits
    • H04B1/50—Circuits using different frequencies for the two directions of communication
    • H04B1/52—Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa
    • H04B1/525—Hybrid arrangements, i.e. arrangements for transition from single-path two-direction transmission to single-direction transmission on each of two paths or vice versa with means for reducing leakage of transmitter signal into the receiver

Definitions

  • the present invention relates to a system for combining a transmitter and a receiver using a circulator and a method for canceling a transmission signal thereof, and more particularly, to a system for combining a transmitter and a receiver using a circulator and a method for canceling a transmission signal thereof, in which a transmission signal incoming to a receiver together with a reception signal is cancelled by generating a 180° phase inverted transmission signal with the same magnitude and delay time as those of the incoming transmission signal, to thereby improve an electrical separation degree of the transmitter and the receiver and simultaneously to reduce volume and cost thereof.
  • a transmission/reception antenna is commonly used in various mobile communication and wireless communication base stations, relay systems or military communication devices
  • a conventional system for combining a transmitter and a receiver which is used for smoothly combining the transmitter and the receiver with the antenna uses an expensive component called a duplexer to combine the transmitter and the receiver, in which an electrical separation degree is sufficiently secured during combining the transmitter and the receiver owing to the electrical characteristics of the duplexer.
  • the duplexer uses a number of dielectric resonators, an electrical loss of the duplexer is considerable. Since the transmission and reception bands are fixed in the duplexer, a pass band frequency is variable. In particular, the duplexer cannot be adapted in a secret conversation communication system which is used in a military communication device whose transmission/reception pass band is inverted frequently.
  • the conventional transmitter/receiver combination circuit uses a duplexer 1 which is connected with an antenna 3 , in which a transmission band pass filter 1 a and a reception band pass filter 1 b for filtering a transmission signal Tx and a reception signal Rx, respectively are integrated into a single body.
  • a sufficient circuitry frequency separation feature can be obtained according to the performance of the respective band pass filters 1 a and 1 b of the duplexer 1 .
  • the fixed transmission/reception band pass filters 1 a and 1 b of the duplexer 1 block the transmission/reception bands in the case that the pass band is successively varied and the pass band is inverted, resulting in causing the duplexer not to be used in the transmitter/receiver combination circuit. Also, since the number of stages of the resonators in each band pass filter 1 a or 1 b of the duplexer increases, signal loss and cost increase due to insertion of dielectric resonators into the pass band.
  • FIG. 2 Another conventional transmission/reception combination circuit shown in FIG. 2 combines a transmitter and a receiver with a circulator 2 , in which an antenna 3 is connected to a first end of the circulator 2 in order to increase a separation degree and transmission and reception band pass filters 1 a and 1 b are connected to second and third ends, respectively.
  • the circulator 2 transfers a supplied signal without causing an electrical signal loss in an arrow direction of the circulator 2 , but has an electrical separation feature in an opposite direction of the arrow.
  • the circulator 2 has a separation degree of 20 dB in general.
  • the circulator 2 has a merit capable of securing the separation degree of about 20 dB.
  • a large power amplification of a transmission signal Tx is accomplished in a power amplifier (not shown) in a transmitter, then a harmonic component due to the amplification is removed in the transmission band pass filter 1 a , and then the resultant signal is emitted toward the antenna 3 , while passing through the circulator 2 , in which case the high power transmission signal Tx from which 20 dB or so is attenuated in the circulator 2 is input to the receiver circuit from the circulator 2 together with the reception signal Rx.
  • the low noise amplifier does not perform a smooth operation and is in saturation state to thereby lose performance of the amplifier.
  • the separation degree of the 20 dB or so is considerably insufficient in view of stability of the transmission/reception communication system.
  • the conventional FIG. 2 technology should add transmission and reception band pass filters 1 a and 1 b in order to supplement the insufficient frequency separation degree as in the FIG. 1 technology.
  • the number of stages of the resonators in each band pass filter should be increased in order to obtain a sufficient separation band, a loss in the pass band occurs.
  • the fixed transmission/reception band pass filters 1 a and 1 b of the duplexer 1 block the transmission/reception bands in the case that the pass band is successively varied and the pass band is inverted, resulting in causing the duplexer not to be used in the transmitter/receiver combination circuit.
  • a transmitter/receiver combination system for combining a transmitter and a receiver into a single antenna in a wireless communication system
  • the transmitter/receiver combination system comprising: a circulator for receiving a transmission signal from the transmitter, transmitting the received transmission signal to an antenna without causing a signal loss, and transmitting a reception signal received from the antenna to other ends without causing a signal loss; and at least one transmission signal canceller for dividing the transmission signal input in an attenuated form as much as a predetermined magnitude via the circulator together with the reception signal into at least two paths, producing two mutually phase inverted transmission signals with the same magnitude and delay time as those of the incoming transmission signal, and recombining the produced two transmission signals with each other, to thereby canceling the transmission signal and transmitting only the reception signal to the receiver.
  • the transmission signal canceller comprises: a first coupler for attenuating a part of the transmission/reception signal Tx+Rx which is input to the transmission signal canceller to branch the same and simultaneously performing a 90° phase delay; a first variable band rejection filter for canceling the reception signal Rx and passing through only a transmission signal Tx with respect to a low power transmission/reception signal Tx+Rx which has been branched via the first coupler; a signal amplifier for amplifying the transmission signal Tx of the first variable band rejection filter into the same magnitude as that of the incoming transmission signal Tx; phase delay means for delaying a time so that the transmission/reception signal Tx+Rx unbranched in the first coupler is consistent with the inverted signal of the branched transmission signal Tx; and a second coupler for 90° phase delaying the output signal of the signal amplifier additionally, and recombining the phase delayed result with the output signal Tx+Rx of the phase delay means, to thereby offset the unbranched transmission signal Tx with the phase
  • the transmitter/receiver combination system further comprises at least one noise signal attenuation means for generating a signal together with the transmission signal from the transmitter disposed between the transmitter and the circulator and attenuating only a noise signal of a reception band input to the receiver.
  • a transmitter/receiver combination system comprises: at least one noise signal attenuation means connected to the output of a transmitter, for attenuating only a noise signal of a reception band generated together with a transmission signal from the transmitter; a circulator for receiving the transmission signal from the noise signal attenuation means, transmitting the received signal to an antenna without causing a signal loss, and transmitting the reception signal received from the antenna to other ends without causing a signal loss; and a first variable filter for canceling the transmission signal input in an attenuated form as much as a predetermined magnitude via the circulator together with the reception signal and transmitting only a reception signal to a receiver.
  • a transmitter/receiver combination system for combining a transmitter and a receiver into a single antenna in a wireless communication system
  • the transmitter/receiver combination system comprising: a first circulator for receiving a transmission signal from the transmitter, transmitting the received transmission signal to a next stage without causing a signal loss; a second circulator for receiving the transmission signal from the first circulator, transmitting the received signal to an antenna without causing a signal loss, and transmitting the reception signal received from the antenna to other ends without causing a signal loss; a first pad and a second pad for receiving a first transmission signal input in an attenuated form as much as a predetermined magnitude via the other end of the first circulator and a second transmission signal input in an attenuated form as much as a predetermined magnitude via the other end of the second circulator, and for converting the first and second transmission signals into two transmission signals whose magnitudes are same and phases are inverted with each other, respectively; and signal combination means for combining the output signals
  • At least one of the first and second pads comprises an attenuator for attenuating the magnitude of a transmission signal in the same magnitude as that of the other transmission signal; and phase delay means for delaying the phase of the signal in order to have a 180° phase difference with respect to the other transmission signal.
  • a transmission signal canceling method in a transmitter/receiver combination system for combining a transmitter and a receiver into a single antenna in a wireless communication system
  • the transmission signal canceling method comprising the steps of: (a) receiving a transmission signal from the transmitter, transmitting the received transmission signal to an antenna via a first path without causing a signal loss, and transmitting a reception signal received from the antenna via a second path; (b) 90° phase delaying for delaying part of the transmission signal the reception signal input to the receiver in an attenuated form as much as a predetermined magnitude via the second path and branching the phase delayed result into a third path; (c) canceling the reception signal among the transmission signal and the reception signal which branched via the third path, and amplifying the transmission signal in the same magnitude as that of the second path; (d) delaying the transmission signal and the reception signal of the unbranched second path to have a phase difference of 180° from the transmission signal of the branched third path; and (e
  • a transmission signal canceling method comprising the steps of: (a) transmitting a transmission signal received from the transmitter, via a first path without causing a signal loss and generating a first transmission signal which has been attenuated as much as a predetermined magnitude via a second path; (b) transmitting the received transmission signal to an antenna without causing a signal loss, and transmitting the reception signal received from the antenna to a third path without causing a signal loss; (c) receiving the first transmission signal via the second path, and a second transmission signal input in an attenuated form as much as a predetermined magnitude via the third path by the transmission signal together with the reception signal, and converting the first and second transmission signals into two transmission signals whose magnitudes are same and phases are inverted with each other; and (d) combining the outputs of the second and third paths so that the first and second transmission signals are cancelled.
  • the present invention offsets a transmission signal incoming to a receiver together with a reception signal is cancelled by generating a 180° phase inverted transmission signal with the same magnitude and delay time as those of the incoming transmission signal, to thereby improve a frequency separation degree of the transmitter and the receiver, reduce a coupling loss and simultaneously to reduce volume and cost thereof.
  • the transmission/reception frequency of the transmission/reception signal and the pass bands of the first through third variable filters are varied, or the transmission/reception band frequency is used in a frequency variable communication system or a secret conversation communication system, which is inverted with each other. Further, the present invention can secure a sufficient separation degree of the transmitter/receiver portion, with a result that a low power variable filter can be used.
  • FIG. 1 is a block diagram schematically showing a conventional transmitter/receiver combination system.
  • FIG. 2 is a block diagram schematically showing another conventional transmitter/receiver combination system.
  • FIG. 3 is a block diagram schematically showing a RF front-end portion including a transmitter/receiver combination system using a single stage circulator according to a first embodiment of the present invention.
  • FIG. 4 is a block diagram schematically showing a RF front-end portion including a transmitter/receiver combination system using a single stage circulator according to a second embodiment of the present invention.
  • FIG. 5 is a block diagram schematically showing a RF front-end portion including a transmitter/receiver combination system using a single stage circulator according to a third embodiment of the present invention.
  • FIG. 6 is a block diagram schematically showing a RF front-end portion including a transmitter/receiver combination system using a double stage circulator according to a fourth embodiment of the present invention.
  • FIG. 3 is a block diagram schematically showing a RF front-end portion including a transmitter/receiver combination system using a single stage circulator according to a first embodiment of the present invention.
  • a transmitter/receiver combination system 30 using a single stage circulator plays a role of combining a transmitter 10 processing a transmission signal Tx and a receiver 20 processing a reception signal Rx, with a common antenna 15 .
  • the transmitter 10 includes a first variable filter 11 for varying a pass band of a transmission signal Tx by several thousand number of times per second and transferring the varied result to a next stage, a power amplifier 12 for large-scale power amplifying the output of the first variable filter 11 , and a harmonic filter 13 for removing a harmonic component included in a power-amplified transmission signal.
  • the large-scale power amplified transmission signal Tx passes through the circulator 14 and is irradiated in the air through a transmission/reception common antenna 15 without causing any loss.
  • the transmitter/receiver combination system 30 includes the circulator 14 and a canceller 16 for canceling a high power transmission signal Tx which is input to the receiver 20 via the circulator 14 , in which the transmission signal Tx is mixed with the feeble reception signal Rx received in the receiver 20 via the antenna 15 and the circulator 14 together with the circulator.
  • the receiver 20 includes a second variable filter 17 whose pass band is varied in order to remove an unnecessary wave other than the reception signal Rx, in which only the feeble reception signal Rx output from the canceller 16 becomes a pass band, and a low noise amplifier 18 for low-noise-amplifying the received feeble reception signal Rx.
  • the canceller 16 includes a first coupler 21 for branching a portion of a transmission/reception signal (Tx+Rx) input to the receiver 20 , that is, an approximately 30 dB attenuated signal and for phase delaying the branched signal by 90°, a first variable band rejection filter 24 for rejecting the reception signal Rx and passing only the transmission signal Tx with respect to the low power transmission/reception signal (Tx+Rx) branched via the first coupler 21 and varying a rejection band frequency, a signal amplifier 25 for amplifying the transmission signal Tx from the first variable band rejection filter 24 into the same magnitude of that of the unbranched transmission signal Tx, a delay line filter 22 for making the delay time of the transmission/reception signal (Tx+Rx) unbranched in the first coupler 21 consistent with that of the branched transmission signal Tx, and a second coupler 23 for additionally phase delaying the output signal Tx of the signal amplifier 25 by 90° and recombining the phase delayed result in a main reception line, to
  • the canceller 16 the signal amplifier 25 , the delay line filter 22 and the first and second couplers 21 and 23 are provided, so that the magnitude and the delay time of the signal are same and the phase thereof differs by 180° between the unbranched and delayed transmission signal Tx and the branched and recombined transmission signal Tx.
  • the pass band of the transmission signal Tx is varied several thousands of times per second in the first variable filter 11 and then the transmission signal Tx is transferred to the power amplifier 12 .
  • the power amplifier 12 amplifies the transmission signal Tx into the intensity of signal sufficient for radiating the same in the air, to then be transferred to the harmonic filter 13 .
  • the harmonic filter 13 cancels a harmonic component occurred due to the amplification and applies the result to the circulator 14 . Accordingly, the transmission signal Tx passing through the circulator 14 without causing a signal loss is radiated in the air via the antenna 15 .
  • the transmission signal Tx input from the circulator 14 to the receiver 20 is still a high power transmission signal Tx, although the input transmission signal Tx is attenuated by about 20 dB in comparison with the radiated transmission signal Tx.
  • the transmission/reception separation degree of the above-described circulator 14 is nothing but about 20 dB. As a result, a certain phenomenon occurs, in which an approximately 20 dB attenuated transmission signal Tx is input to the receiver 20 . In general, a signal received through the antenna 15 is considerably feeble. Thus, the feeble reception signal Rx and the approximately 20 dB attenuated high power transmission signal Tx are input to the receiver 20 via the circulator 14 .
  • the first coupler 21 branches a portion of a transmission/reception signal (Tx+Rx) input to the receiver 20 , that is, an approximately 30 dB attenuated signal and phase-delays the branched signal by 90°.
  • the first variable band rejection filter 24 rejects the reception signal Rx and passes only the transmission signal Tx with respect to the low power transmission/reception signal (Tx+Rx) which is branched and 90° phase delayed via the first coupler 21 .
  • the signal amplifier 25 amplifies the transmission signal Tx from the first variable band rejection filter 24 into the same magnitude as that of the unbranched transmission signal Tx, and transfers the amplified result to the second coupler 23 .
  • the output signal Tx of the signal amplifier 25 is combined to the second coupler 23 , is secondarily phase delayed by 90° with a result that a 180° phase delay occurs in whole.
  • the transmission/reception signal (Tx+Rx) unbranched in the first coupler 21 is branched in the delay line filter 22 , delayed to have a phase difference of 180° from the recombined transmission signal Tx, and supplied to the second coupler 23 .
  • the recombined 180° phase inverted transmission signal ⁇ Tx is mixed with the output signal Tx+Rx of the delay line filter 22 .
  • the high power two transmission signal Tx and ( ⁇ Tx) are offset with each other, and only a feeble reception signal is output to the second variable filter 17 .
  • the second coupler 23 phase delays the second transmission signal Tx by 180°, mixed with the first transmission signal Tx and cancelled.
  • the high power transmission signal Tx becomes considerably feeble.
  • the low power second variable filter 17 has a pass band in which only a feeble reception signal Rx is passed, an unnecessary wave other than the reception signal Rx is cancelled, and then sent to the low noise amplifier 18 .
  • the low noise amplifier 18 can amplify the clean reception signal Rx.
  • the first embodiment of the present invention varies the band pass frequencies of the first and second variable filters 11 and 17 installed in the transmitter/receiver 10 and 20 and the canceller 16 and the band rejection frequency of the first variable band rejection filter 24 , to thereby vary the transmission/reception frequencies. Further, the first embodiment of the present invention can be applied even in the case that the transmission/reception frequencies are inverted.
  • variable filter is made of a semiconductor device, and thus it is difficult to realize it for use: as a high power. Also, since a relatively high power transmission signal Tx is input to the receiver 20 in the prior art, the variable filter cannot be used.
  • the present invention offsets the high power transmission signal Tx efficiently by the canceller 16 due to the insufficient separation degree of the circulator 14 . Accordingly, the problem occurred in the case that the transmission/reception pass band is inverted has been solved. It is also possible to use low power variable filters 11 , 17 and 24 which can be implemented relatively with ease.
  • FIG. 4 is a block diagram schematically showing a RF front-end portion including a transmitter/receiver combination system using a single stage circulator according to a second embodiment of the present invention.
  • a transmitter/receiver combination system 40 using a single stage circulator includes a second canceller 16 a for efficiently attenuating a noise signal Nx amplified while passing through the power amplifier 12 in a transmitter 10 a , instead of the harmonic filter 13 in the first embodiment.
  • the transmitter/receiver combination system 40 includes the second canceller 16 a , a circulator 14 , and a canceller 16 , in order to greatly attenuate the component of a noise signal Nx included in the power amplified transmission signal Tx.
  • the transmitter 10 a includes a first variable filter 11 for varying the pass band of the transmission signal Tx several thousands of times per second and transferring the varied result to a next stage, and a power amplifier 12 for large power amplifying the output of the first variable filter 11 .
  • the canceller 16 a includes a third coupler 21 a for branching a portion of the noise signal Nx and the transmission signal Tx amplified together with the transmission signal Tx during amplifying in the power amplifier 12 , that is, an approximately 30 dB attenuated signal and for phase delaying the branched signal by 90°, a second variable band rejection filter 24 a for rejecting the transmission signal Tx and passing only the noise signal Nx with respect to the low power transmission/noise signal (Tx+Nx) branched via the third coupler 21 a , a signal amplifier 25 a for amplifying the noise signal Nx from the second variable band rejection filter 24 a into the same magnitude of that of the unbranched noise signal Nx, a harmonic cancel/delay line filter 22 a for delaying the transmission/noise signal Tx+Nx unbranched from the third coupler 21 a to have a phase difference of 180° from the unbranched and recombined noise signal Nx and simultaneously canceling harmonic components occurred due to the
  • the canceller 16 a the signal amplifier 25 a , the delay line filter 22 a and the third and fourth couplers 21 a and 23 a are provided, so that the magnitude and the delay time of the signal are same and the phase thereof differs by 180° between the unbranched and delayed noise signal Nx and the branched and recombined noise signal Nx.
  • the reception signal Rx received in the antenna 15 passes through the circulator 14 , in which case at maximum 0.8 dB is attenuated.
  • the reception signal Rx is delayed for a predetermined time in the delay line filter 22 , in which case at maximum 0.3 dB is attenuated.
  • the second variable filter at maximum 3 dB is attenuated.
  • an attenuation loss along the main reception path is 4.5 dB.
  • the loss of about 5 dB occurs including a cable assembly loss of each element.
  • the transmission signal Tx is amplified into a level of 20 W necessary for offsetting the transmission signal Tx in the signal amplifier 25 and thereafter the amplified signal is phase delayed in the 10 dB second coupler 23 by 90°, mixed and loaded in the main reception path, to thereby offset two transmission signals Tx.
  • a clean reception signal Rx is obtained while passing through the second variable filter 17 and the low noise filter 18 .
  • the transmission signal Tx is filtered in the first variable filter 11 , by use of only the transmission signal Tx, and amplified as 20 W, that is, 43 dBm in the power amplifier 12 together with the not-yet-filtered noise signal Nx.
  • the amplified signal is attenuated by 0.2 dB in the third coupler 21 a having a coupling loss of 20 dB, and transferred to the harmonic cancel/delay line filter 22 a , to thereby remove a harmonic component due to the power amplification and simultaneously delay a predetermined time.
  • the output signal of the harmonic cancel/delay line filter 22 a is supplied to the 10 dB fourth coupler 23 a to accomplish 0.6 dB attenuation.
  • a portion of the signal which has been attenuated by 20 dB together with the 90° phase delay in the 20 dB third coupler 21 a is branched in order to lower a noise signal level of the reception band by 75 dBm at the output end of the power amplifier 12 .
  • the second variable band rejection filter 24 a rejects the transmission signal Tx and passes only the noise signal Nx. Then, an approximately 35 dB low noise gain amplification is performed in the signal amplifier 25 a .
  • the output signal of the signal amplifier 25 a is phase delayed by 90° again in the 10 dB fourth coupler 23 a , mixed and loaded in the main transmission path, to thereby effect an attenuation of the noise signal Nx in the reception band more than 40 dB according to the 180° phase difference.
  • the transmission signal Tx passes through the circulator 14 to effect an attenuation of 15 dB or more and then is input to the reception side.
  • the second embodiment since the second embodiment performs a signal processing at the reception side in the state where the noise signal Nx of 40 dB or more has been attenuated, when compared with the first embodiment. Therefore, the second embodiment can obtain the reception signal Rx having a much higher separation degree.
  • the second embodiment of the present invention varies the band pass frequencies of the first and second variable filters 11 and 17 installed in the transmitter/receiver 10 and 20 and the cancellers 16 and 16 a and the band rejection frequencies of the first and second variable band rejection filters 24 and 24 a , to thereby vary the transmission/reception frequencies. Further, the second embodiment of the present invention can be applied even in the case that the transmission/reception frequencies are inverted.
  • FIG. 5 is a block diagram schematically showing a RF front-end portion including a transmitter/receiver combination system using a single stage circulator according to a third embodiment of the present invention.
  • the third embodiment of the present invention does not use a canceller 16 in the transmitter/receiver combination system 40 of the second embodiment, but uses a third variable filter 26 whose pass band is varied in order to remove an unnecessary wave other than the reception signal Rx in which only the reception signal Rx is used as a pass band in simple manner. Accordingly, the third variable filter 26 is used to implement a canceller at the reception side in the third embodiment.
  • the receiver 20 a includes a low noise amplifier 18 connected to the third variable filter, for low-noise-amplifying the reception signal Rx, and a second variable filter 17 connected to the low noise amplifier, whose pass band is varied in order to remove an unnecessary wave other than the reception signal Rx in which only the reception signal Rx is used as a pass band.
  • the transmitter 10 a includes a first variable filter 11 and a power amplifier 12 as in the second embodiment. Also, since the second canceller 16 a and the circulator 14 are configured in the same manner as that of the second embodiment, the detailed description thereof will be omitted.
  • the transmitter/receiver combination system 40 a in the third embodiment includes a second canceller 16 a , the circulator 14 and the third variable filter 26 .
  • the reception signal Rx received in the antenna 15 passes through the circulator 14 , in which case at maximum 0.8 dB is attenuated.
  • the third variable filter 26 an unnecessary wave other than the reception signal Rx is removed, in which at maximum 3 dB is attenuated.
  • a total attenuation loss is 3.8 dB. The loss of about 4.5 dB or so occurs including a cable assembly loss.
  • reception signal Rx Thereafter, a low noise amplification is accomplished with respect to the reception signal Rx, and then a clean reception signal Rx is obtained while passing through the second variable filter 17 which removes the unnecessary wave other than the reception signal Rx.
  • the third embodiment can implement the receiver 20 a using a low power variable filter.
  • the transmission signal Tx passes through the first variable filter 11 and the power amplifier 12 . Then, the transmission signal Tx passes through the circulator 14 and transferred to the antenna 15 in the state where the noise signal Nx of the reception band is attenuated by 40 dB or more in the second canceller 16 a , and part of the transmission signal Tx is additionally attenuated by 15 dB or more in the circulator 14 and input to the reception side.
  • the third embodiment also performs a signal processing at the reception side in the state where the noise signal Nx of 40 dB or more is attenuated as in the second embodiment, to thereby obtain the reception signal Rx with a high separation degree.
  • the third embodiment of the present invention varies the band pass frequencies of the first through third variable filters 11 , 17 , and 26 installed in the transmitter/receiver 10 a and 20 a and the canceller 16 a and the band rejection frequencies of the second variable band rejection filters 24 a , to thereby vary the transmission/reception frequencies. Further, the third embodiment of the present invention can be applied even in the case that the transmission/reception frequencies are inverted.
  • FIG. 6 is a block diagram schematically showing a RF front-end portion including a transmitter/receiver combination system using a double stage circulator according to a fourth embodiment of the present invention.
  • the transmitter/receiver combination system 30 a using a double stage circulator plays a role of coupling a transmitter 10 including a variable filter 11 , a power amplifier 12 , a harmonic filter 13 , and a receiver 20 including a variable filter 17 and a low noise amplifier 18 with a common antenna 15 .
  • the combination system 30 a includes first and second circulators 31 and 32 , first and second pads 33 and 34 and a power divider 35 .
  • the first and second circulators 31 and 32 are connected in series in the form of a double stage between the transmitter 10 and the antenna 15 . Accordingly, the transmission signal Tx passes through the first and second circulators 31 and 32 and transferred to the antenna 15 without causing a signal loss, to then be radiated in the air via the antenna 15 .
  • first and second pads 33 and 34 are connected at each remaining output end of the first and second circulators 31 and 32 .
  • the outputs of the first and second pads 33 and 34 are connected to the power divider 35 and the output of the power divider 35 is connected to the variable filter 17 in the receiver 20 a.
  • first and second pads 33 and 34 To the first and second pads 33 and 34 are input transmission signals Tx 1 and Tx 2 whose magnitudes are same or similar but powers are attenuated by 20 dB or so, via each remaining output end of the first and second circulators 31 and 32 . Also, the feeble reception signal Rx received via the antenna 15 is applied to the second pad 34 together with the attenuated transmission signal Tx 2 via the second circulator 32 .
  • the first and second pads 33 and 34 include an attenuator and a delay line, or a delay line filter, respectively, and process the first and second transmission signals Tx 1 and Tx 2 into signals whose magnitudes are same but phases are inverted by 180°, respectively and transfer the same to the power divider 35 .
  • an attenuator and a delay are provided in the first pad 33 in order to avoid the attenuation of the reception signal Rx, with a result that the input first transmission signal Tx 1 is set a signal whose magnitude is same as the second transmission signal Tx 2 and phase differs by 180°.
  • the combination system 30 a of the present invention does not affect transmission/reception of the signal, but has an advantage of effectively canceling the high power transmission signal Tx input to the receiver 20 .
  • the reception signal Rx of the power divider 35 in the combination system 30 a passes through the variable filter 17 and the low noise amplifier 18 in the receiver 20 in sequence and can amplify a clean reception signal Rx without having any noise.
  • the combination system 30 a of the fourth embodiment varies the band pass frequencies of the variable filters 11 and 17 installed in the transmitter/receiver 10 and 20 and the first and second pads 33 and 34 , to thereby vary the transmission/reception frequencies.
  • the fourth embodiment of the present invention can be applied even in the case that the transmission/reception frequencies are inverted. That is, the combination system 30 a can be applied even to the case where any transmitter and receiver are combined as in the variation and inversion of the transmission/reception frequencies.
  • the present invention can be effectively used in a frequency varying system where a transmission/reception band frequency is variable and furthermore a transmission/reception band frequency is inverted.
  • the present invention can be applied at lower cost and more excellent performance, than those in comparison with an existing system using a duplexer having large volume, high cost and large loss.
  • the present invention provide a transmission/reception band combination method using a circulator, having an advantage having a loss characteristic lower than the duplexer, and remarkably improving an electrical separation degree of the transmitter/receiver which raises a problem due to the combination method using the existing circulator.
  • a single canceller has been provided at the transmission side and/or the reception side.
  • the cancellers of a double stage are connected in series at the transmission/reception sides, to thereby remove the transmission signal input to the receiver more perfectly.
  • the combination system forms a single branch to remove a transmission signal.
  • a proper number of branches are formed, to thereby remove all unnecessary signals including a center signal and harmonic wave signals, which is apparent to a person skilled in the art.
  • the present invention generates an inverted transmission signal having the same magnitude and a 180° phase difference as and from that of a transmission signal which is input to a receiver together with a reception signal.
  • the frequency separation degree of the transmitter/receiver can be enhanced and simultaneously a coupling loss is small and the volume and cost of the product can be lowered, due to the recombination and canceling.
  • the present invention effectively the high power transmission signal input to the receiver, to thereby use a low power variable filter. Accordingly, the sufficient separation degree of the transmitter/receiver can be obtained even in the case that the transmission/reception frequency is variable and the band of the transmission/reception frequency is inverted as in a secret conversation communication.
  • the transmission signal input to the receiver can be cancelled in the state where the noise signal of the reception band is attenuated by the canceller provided in the transmitter, to thereby obtain a reception signal Rx while having a high separation degree.
US09/656,945 1999-11-23 2000-09-07 System combining radio frequency transmitter and receiver using circulator and method for canceling transmission signal thereof Expired - Fee Related US6567648B1 (en)

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Cited By (63)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040092281A1 (en) * 2002-10-24 2004-05-13 Bbnt Solutions Llc Spectrum-adaptive networking
US20040106381A1 (en) * 2002-09-06 2004-06-03 Engim Incorporated Transmit signal cancellation in wireless receivers
EP1508975A1 (en) * 2003-08-18 2005-02-23 Alcatel Radio frequency device using circulator and echo canceller for cancelling transmission leakage signal in the reception chain
US20050207509A1 (en) * 2004-03-19 2005-09-22 Saunders Stuart B Method and apparatus for canceling the transmitted signal in a homodyne duplex transceiver
US20050255810A1 (en) * 2004-05-13 2005-11-17 Samsung Electronics Co., Ltd. Apparatus for transmit and receive switching in a time-division duplexing wireless network
US20060040620A1 (en) * 2004-08-18 2006-02-23 Jae-Ho Jung Apparatus and method for separating transmit and receive signals for time division duplexing radio system
US20070105509A1 (en) * 2005-11-09 2007-05-10 Texas Instruments Inc. RF transmission leakage mitigator, method of mitigating an RF transmission leakage and CDMA tranceiver employing the same
US20070117511A1 (en) * 2005-11-18 2007-05-24 Samsung Electronics Co., Ltd. RF receiving apparatus and method for removing leakage component of received signal using local signal
US20070243833A1 (en) * 2002-12-18 2007-10-18 Matsushita Electric Industrial Co., Ltd. Radio communication apparatus, radio communication method, antenna apparatus and first duplexer
US20080076360A1 (en) * 2006-09-22 2008-03-27 Northrop Grumman Corporation Apparatus for combining two radios on a single antenna
US20080198772A1 (en) * 2007-02-16 2008-08-21 Samsung Electronics Co., Ltd. System and method for transmitter leak-over cancellation with closed loop optimization
US20080300194A1 (en) * 2007-04-10 2008-12-04 Sapphire Therapeutics, Inc. Methods of treating emesis using growth hormone secretagogues
US20090068965A1 (en) * 2007-09-06 2009-03-12 Northrop Grumman Systems Corporation Method, Apparatus and System for an Omni Digital Package for Reducing Interference
US20090068974A1 (en) * 2007-09-06 2009-03-12 Smith Francis J Multi-mode - multi-band direct conversion receiver with complex i and q channel interference mitigation processing for cancellation of intermodulation products
US20090088095A1 (en) * 2007-09-25 2009-04-02 Kabushiki Kaisha Toshiba Amplifier, radio transmitting apparatus, and radio receiving apparatus
US20090227213A1 (en) * 2008-03-10 2009-09-10 Arash Sadeghfam Compensation circuit for an rfid-reader unit and rfid reader device
US20090233568A1 (en) * 2008-03-11 2009-09-17 Qualcomm Incorporated High-linearity receiver with transmit leakage cancellation
DE102008013469A1 (de) 2008-03-10 2009-09-17 Pepperl + Fuchs Gmbh Elektrischer Zirkulator für RFID-Readereinheiten
DE102008013468A1 (de) 2008-03-10 2009-09-17 Pepperl + Fuchs Gmbh Elektrisch verstimmbares Kanalfilter mit Trägerunterdrückung für RFID-Reader-Einheiten
US20090284354A1 (en) * 2008-05-19 2009-11-19 Sirit Technologies Inc. Multiplexing Radio Frequency Signals
WO2010020629A1 (de) * 2008-08-22 2010-02-25 Robert Bosch Gmbh Signalverteilungsvorrichtung
US20100048156A1 (en) * 2008-08-21 2010-02-25 Intersil Americas Inc. Noise cancellation for antenna module
US7719384B1 (en) 2008-09-25 2010-05-18 The United States Of America As Represented By The Secretary Of The Navy Broadband channelized circulator
US20100176921A1 (en) * 2009-01-09 2010-07-15 Sirit Technologies Inc. Determining speeds of radio frequency tags
US20100289623A1 (en) * 2009-05-13 2010-11-18 Roesner Bruce B Interrogating radio frequency identification (rfid) tags
US20100302012A1 (en) * 2009-06-02 2010-12-02 Sirit Technologies Inc. Switching radio frequency identification (rfid) tags
US20110205025A1 (en) * 2010-02-23 2011-08-25 Sirit Technologies Inc. Converting between different radio frequencies
US20110301040A1 (en) * 2010-06-08 2011-12-08 Liberty University High temperature superconductor filters for high frequency shipboard applications
US20110304431A1 (en) * 2010-06-11 2011-12-15 Farrell Edward M Devices employing delay matching to mitigate local oscillator noise and methods thereof
US20120112956A1 (en) * 2009-07-16 2012-05-10 Freescale Semiconductor, Inc. Integrated circuit, transceiver and method for leakage cancellation in a receive path
US8226003B2 (en) 2006-04-27 2012-07-24 Sirit Inc. Adjusting parameters associated with leakage signals
US8248212B2 (en) 2007-05-24 2012-08-21 Sirit Inc. Pipelining processes in a RF reader
WO2013008117A1 (en) * 2011-07-12 2013-01-17 Telefonaktiebolaget L M Ericsson (Publ) Electronic duplexer
US8427316B2 (en) 2008-03-20 2013-04-23 3M Innovative Properties Company Detecting tampered with radio frequency identification tags
EP2733855A1 (en) * 2012-11-15 2014-05-21 Telefonaktiebolaget L M Ericsson (publ) Transceiver front-end
US8907842B1 (en) * 2009-03-25 2014-12-09 Raytheon Company Method and apparatus for attenuating a transmitted feedthrough signal
WO2016016691A1 (en) * 2014-07-31 2016-02-04 Telefonaktiebolaget L M Ericsson (Publ) Duplexer system and associated digital correction for improved isolation
US9260123B2 (en) 2013-08-23 2016-02-16 Electro-Motive Diesel, Inc. System and method for determining locomotive position in a consist
US9270335B2 (en) 2013-08-23 2016-02-23 Electro-Motive Diesel, Inc. Receive attenuation system for trainline communication networks
US9463816B2 (en) 2013-08-23 2016-10-11 Electro-Motive Diesel, Inc. Trainline communication network access point including filter
US9560139B2 (en) 2014-04-11 2017-01-31 Electro-Motive Diesel, Inc. Train communication network
US9667404B2 (en) 2012-06-07 2017-05-30 Telefonaktiebolaget Lm Ericsson (Publ) Duplexer-less transceiver and communication apparatus
US9688295B2 (en) 2013-08-23 2017-06-27 Electro-Motive Diesel, Inc. Trainline network access point for parallel communication
US9711836B1 (en) 2015-10-30 2017-07-18 The United States of America as requested by the Secretary of the Air Force Tunable high isolation circulator
US9744979B2 (en) 2014-04-11 2017-08-29 Electro-Motive Diesel, Inc. Train communication network
US9871552B2 (en) 2013-04-30 2018-01-16 Telefonaktiebolaget Lm Ericsson (Publ) Transceiver arrangement, communication device, method and computer program
US9900044B2 (en) 2014-01-21 2018-02-20 Telefonaktiebolaget Lm Ericsson (Publ) Transceiver arrangement and communication device
US9923593B2 (en) 2013-03-14 2018-03-20 Telefonaktiebolaget Lm Ericsson (Publ) Transmitter receiver leakage reduction in a full duplex system without the use of a duplexer
WO2018118337A1 (en) * 2016-12-22 2018-06-28 Intel Corporation Waveguide communication with increased link data rate
US10027465B2 (en) 2013-04-26 2018-07-17 Telefonaktiebolaget Lm Ericsson Transceiver arrangement, communication device, method and computer program
US10062025B2 (en) 2012-03-09 2018-08-28 Neology, Inc. Switchable RFID tag
US10200079B2 (en) 2014-10-29 2019-02-05 Telefonaktiebolaget Lm Ericsson (Publ) Transceiver arrangement and communication device
US10321357B1 (en) * 2016-07-16 2019-06-11 GenXComm, Inc. Interference cancellation methods and apparatus
US10804955B2 (en) * 2017-12-20 2020-10-13 Murata Manufacturing Co., Ltd. High-frequency module
US11150409B2 (en) 2018-12-27 2021-10-19 GenXComm, Inc. Saw assisted facet etch dicing
EP2777210B1 (en) * 2011-11-07 2021-10-20 Telefonaktiebolaget LM Ericsson (publ) Dynamic space division duplex (sdd) wireless communications with multiple antennas using self-interference cancellation
US11215755B2 (en) 2019-09-19 2022-01-04 GenXComm, Inc. Low loss, polarization-independent, large bandwidth mode converter for edge coupling
US11309965B2 (en) 2019-07-15 2022-04-19 GenXComm, Inc. Efficiently combining multiple taps of an optical filter
US11356235B2 (en) * 2017-05-24 2022-06-07 The Board Of Trustees Of The University Of Illinois Self-interference cancellation for in-band full duplex single antenna communication systems
US11469821B2 (en) 2015-12-13 2022-10-11 GenXComm, Inc. Interference cancellation methods and apparatus
US11539394B2 (en) 2019-10-29 2022-12-27 GenXComm, Inc. Self-interference mitigation in in-band full-duplex communication systems
US11796737B2 (en) 2020-08-10 2023-10-24 GenXComm, Inc. Co-manufacturing of silicon-on-insulator waveguides and silicon nitride waveguides for hybrid photonic integrated circuits
US11838056B2 (en) 2021-10-25 2023-12-05 GenXComm, Inc. Hybrid photonic integrated circuits for ultra-low phase noise signal generators

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100329262B1 (ko) * 2000-03-21 2002-03-18 박종희 중계기에서 고주파 수동소자 상호변조 왜곡신호의 제거회로
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KR100703366B1 (ko) * 2004-12-21 2007-04-03 삼성전자주식회사 무선 송수신기의 노이즈 제거 장치
KR101974549B1 (ko) * 2017-08-30 2019-05-02 한화시스템 주식회사 이동형 기지국 장치 및 이를 이용한 무선 통신 방법
KR102468276B1 (ko) * 2021-06-29 2022-11-17 엘아이지넥스원 주식회사 Sdr 무전기의 운용 주파수 근접 불요파 신호 제거 장치 및 방법

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4725842A (en) * 1982-09-27 1988-02-16 Teledyne Industries, Inc. Isolation apparatus for a continuous-wave radar system
US5129099A (en) * 1989-03-30 1992-07-07 Electromagnetic Sciences, Inc. Reciprocal hybrid mode rf circuit for coupling rf transceiver to an rf radiator
US5307514A (en) * 1988-07-13 1994-04-26 Telemus Electronic Systems Inc. Frequency independent strong signal suppressor
US5335360A (en) * 1991-06-25 1994-08-02 Motorola, Inc. Base site selection apparatus and method
US5444864A (en) * 1992-12-22 1995-08-22 E-Systems, Inc. Method and apparatus for cancelling in-band energy leakage from transmitter to receiver
US5701595A (en) * 1995-05-04 1997-12-23 Nippondenso Co., Ltd. Half duplex RF transceiver having low transmit path signal loss
US5923647A (en) * 1996-09-06 1999-07-13 Ericsson Inc. Circulator usage in time division duplex radios
US6107898A (en) * 1998-04-30 2000-08-22 The United State Of America As Represented By The Secretary Of The Navy Microwave channelized bandpass filter having two channels
US6311045B1 (en) * 1997-07-28 2001-10-30 Roke Manor Research Limited Apparatus for signal isolation in a radio transmitter-receiver
US6313713B1 (en) * 1999-09-28 2001-11-06 The United States Of America As Represented By The Secretary Of The Navy Matched pair circulator antenna isolation circuit

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4725842A (en) * 1982-09-27 1988-02-16 Teledyne Industries, Inc. Isolation apparatus for a continuous-wave radar system
US5307514A (en) * 1988-07-13 1994-04-26 Telemus Electronic Systems Inc. Frequency independent strong signal suppressor
US5129099A (en) * 1989-03-30 1992-07-07 Electromagnetic Sciences, Inc. Reciprocal hybrid mode rf circuit for coupling rf transceiver to an rf radiator
US5335360A (en) * 1991-06-25 1994-08-02 Motorola, Inc. Base site selection apparatus and method
US5444864A (en) * 1992-12-22 1995-08-22 E-Systems, Inc. Method and apparatus for cancelling in-band energy leakage from transmitter to receiver
US5701595A (en) * 1995-05-04 1997-12-23 Nippondenso Co., Ltd. Half duplex RF transceiver having low transmit path signal loss
US5923647A (en) * 1996-09-06 1999-07-13 Ericsson Inc. Circulator usage in time division duplex radios
US6311045B1 (en) * 1997-07-28 2001-10-30 Roke Manor Research Limited Apparatus for signal isolation in a radio transmitter-receiver
US6107898A (en) * 1998-04-30 2000-08-22 The United State Of America As Represented By The Secretary Of The Navy Microwave channelized bandpass filter having two channels
US6313713B1 (en) * 1999-09-28 2001-11-06 The United States Of America As Represented By The Secretary Of The Navy Matched pair circulator antenna isolation circuit

Cited By (105)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040106381A1 (en) * 2002-09-06 2004-06-03 Engim Incorporated Transmit signal cancellation in wireless receivers
USRE47720E1 (en) * 2002-10-24 2019-11-05 Usta Technology, Llc Spectrum-adaptive networking
US7483711B2 (en) * 2002-10-24 2009-01-27 Bbn Technologies Corp Spectrum-adaptive networking
US20040092281A1 (en) * 2002-10-24 2004-05-13 Bbnt Solutions Llc Spectrum-adaptive networking
US20070243833A1 (en) * 2002-12-18 2007-10-18 Matsushita Electric Industrial Co., Ltd. Radio communication apparatus, radio communication method, antenna apparatus and first duplexer
US7725082B2 (en) * 2002-12-18 2010-05-25 Panasonic Corp. Radio communication apparatus, radio communication method, antenna apparatus and first duplexer
EP1508975A1 (en) * 2003-08-18 2005-02-23 Alcatel Radio frequency device using circulator and echo canceller for cancelling transmission leakage signal in the reception chain
US20050207509A1 (en) * 2004-03-19 2005-09-22 Saunders Stuart B Method and apparatus for canceling the transmitted signal in a homodyne duplex transceiver
WO2005089427A3 (en) * 2004-03-19 2006-11-09 Samsys Techologies Inc A method and apparatus for canceling the transmitted signal
US20070249314A1 (en) * 2004-03-19 2007-10-25 Sirit Technologies Inc. Adjusting parameters associated with transmitter leakage
US7327802B2 (en) * 2004-03-19 2008-02-05 Sirit Technologies Inc. Method and apparatus for canceling the transmitted signal in a homodyne duplex transceiver
US20050255810A1 (en) * 2004-05-13 2005-11-17 Samsung Electronics Co., Ltd. Apparatus for transmit and receive switching in a time-division duplexing wireless network
US7373115B2 (en) * 2004-05-13 2008-05-13 Samsung Electronics Co., Ltd. Apparatus for transmit and receive switching in a time-division duplexing wireless network
US20060040620A1 (en) * 2004-08-18 2006-02-23 Jae-Ho Jung Apparatus and method for separating transmit and receive signals for time division duplexing radio system
US7349674B2 (en) * 2004-08-18 2008-03-25 Electronics And Telecommunications Research Institute Apparatus and method for separating transmit and receive signals for time division duplexing radio system
US20070105509A1 (en) * 2005-11-09 2007-05-10 Texas Instruments Inc. RF transmission leakage mitigator, method of mitigating an RF transmission leakage and CDMA tranceiver employing the same
US7706755B2 (en) * 2005-11-09 2010-04-27 Texas Instruments Incorporated Digital, down-converted RF residual leakage signal mitigating RF residual leakage
US7689170B2 (en) * 2005-11-18 2010-03-30 Samsung Electronics Co., Ltd. RF receiving apparatus and method for removing leakage component of received signal using local signal
US20070117511A1 (en) * 2005-11-18 2007-05-24 Samsung Electronics Co., Ltd. RF receiving apparatus and method for removing leakage component of received signal using local signal
US8226003B2 (en) 2006-04-27 2012-07-24 Sirit Inc. Adjusting parameters associated with leakage signals
US20080076360A1 (en) * 2006-09-22 2008-03-27 Northrop Grumman Corporation Apparatus for combining two radios on a single antenna
US20080198772A1 (en) * 2007-02-16 2008-08-21 Samsung Electronics Co., Ltd. System and method for transmitter leak-over cancellation with closed loop optimization
US7672643B2 (en) * 2007-02-16 2010-03-02 Samsung Electronics Co., Ltd. System and method for transmitter leak-over cancellation with closed loop optimization
US20080300194A1 (en) * 2007-04-10 2008-12-04 Sapphire Therapeutics, Inc. Methods of treating emesis using growth hormone secretagogues
US8248212B2 (en) 2007-05-24 2012-08-21 Sirit Inc. Pipelining processes in a RF reader
US7826808B2 (en) * 2007-09-06 2010-11-02 Northrop Grumman Systems Corporation Method, apparatus and system for an omni digital package for reducing interference
US7773967B2 (en) * 2007-09-06 2010-08-10 Francis J. Smith Multi-mode—multi-band direct conversion receiver with complex I and Q channel interference mitigation processing for cancellation of intermodulation products
US20090068974A1 (en) * 2007-09-06 2009-03-12 Smith Francis J Multi-mode - multi-band direct conversion receiver with complex i and q channel interference mitigation processing for cancellation of intermodulation products
US20090068965A1 (en) * 2007-09-06 2009-03-12 Northrop Grumman Systems Corporation Method, Apparatus and System for an Omni Digital Package for Reducing Interference
US20090088095A1 (en) * 2007-09-25 2009-04-02 Kabushiki Kaisha Toshiba Amplifier, radio transmitting apparatus, and radio receiving apparatus
US7983637B2 (en) * 2007-09-25 2011-07-19 Kabushiki Kaisha Toshiba Amplifier, radio transmitting apparatus, and radio receiving apparatus
US20090224887A1 (en) * 2008-03-10 2009-09-10 Arash Sadeghfam Adjustable circuit and rfid reader device
DE102008013468A1 (de) 2008-03-10 2009-09-17 Pepperl + Fuchs Gmbh Elektrisch verstimmbares Kanalfilter mit Trägerunterdrückung für RFID-Reader-Einheiten
DE102008013469A1 (de) 2008-03-10 2009-09-17 Pepperl + Fuchs Gmbh Elektrischer Zirkulator für RFID-Readereinheiten
EP2101278A2 (de) 2008-03-10 2009-09-16 Pepperl + Fuchs GmbH Kompensationsschaltung für eine RFID-Readereinheit und RFID-Readereinheit
EP2101279A2 (de) 2008-03-10 2009-09-16 Pepperl + Fuchs GmbH Einstellbare Schaltung und RFID-Readereinheit
US8285214B2 (en) * 2008-03-10 2012-10-09 Pepperl + Fuchs Gmbh Adjustable circuit and RFID reader device
US20090227213A1 (en) * 2008-03-10 2009-09-10 Arash Sadeghfam Compensation circuit for an rfid-reader unit and rfid reader device
US20090233568A1 (en) * 2008-03-11 2009-09-17 Qualcomm Incorporated High-linearity receiver with transmit leakage cancellation
US8526903B2 (en) * 2008-03-11 2013-09-03 Qualcomm, Incorporated High-linearity receiver with transmit leakage cancellation
US8427316B2 (en) 2008-03-20 2013-04-23 3M Innovative Properties Company Detecting tampered with radio frequency identification tags
US8446256B2 (en) 2008-05-19 2013-05-21 Sirit Technologies Inc. Multiplexing radio frequency signals
US20090284354A1 (en) * 2008-05-19 2009-11-19 Sirit Technologies Inc. Multiplexing Radio Frequency Signals
US8422974B2 (en) * 2008-08-21 2013-04-16 Intersil Americas Inc. Noise cancellation for antenna module
US20100048156A1 (en) * 2008-08-21 2010-02-25 Intersil Americas Inc. Noise cancellation for antenna module
WO2010020629A1 (de) * 2008-08-22 2010-02-25 Robert Bosch Gmbh Signalverteilungsvorrichtung
US7719384B1 (en) 2008-09-25 2010-05-18 The United States Of America As Represented By The Secretary Of The Navy Broadband channelized circulator
US20100176921A1 (en) * 2009-01-09 2010-07-15 Sirit Technologies Inc. Determining speeds of radio frequency tags
US8169312B2 (en) 2009-01-09 2012-05-01 Sirit Inc. Determining speeds of radio frequency tags
US8907842B1 (en) * 2009-03-25 2014-12-09 Raytheon Company Method and apparatus for attenuating a transmitted feedthrough signal
US20100289623A1 (en) * 2009-05-13 2010-11-18 Roesner Bruce B Interrogating radio frequency identification (rfid) tags
US20100302012A1 (en) * 2009-06-02 2010-12-02 Sirit Technologies Inc. Switching radio frequency identification (rfid) tags
US8416079B2 (en) 2009-06-02 2013-04-09 3M Innovative Properties Company Switching radio frequency identification (RFID) tags
US8917204B2 (en) * 2009-07-16 2014-12-23 Freescale Semiconductor, Inc. Integrated circuit, transceiver and method for leakage cancellation in a receive path
US20120112956A1 (en) * 2009-07-16 2012-05-10 Freescale Semiconductor, Inc. Integrated circuit, transceiver and method for leakage cancellation in a receive path
US20110205025A1 (en) * 2010-02-23 2011-08-25 Sirit Technologies Inc. Converting between different radio frequencies
US20110301040A1 (en) * 2010-06-08 2011-12-08 Liberty University High temperature superconductor filters for high frequency shipboard applications
US8965307B2 (en) * 2010-06-08 2015-02-24 Liberty University Cryogenic high power filters for high frequency shipboard applications
US8766775B2 (en) * 2010-06-11 2014-07-01 Intelleflex Corporation Devices employing delay matching to mitigate local oscillator noise and methods thereof
US20110304431A1 (en) * 2010-06-11 2011-12-15 Farrell Edward M Devices employing delay matching to mitigate local oscillator noise and methods thereof
WO2013008117A1 (en) * 2011-07-12 2013-01-17 Telefonaktiebolaget L M Ericsson (Publ) Electronic duplexer
EP2777210B1 (en) * 2011-11-07 2021-10-20 Telefonaktiebolaget LM Ericsson (publ) Dynamic space division duplex (sdd) wireless communications with multiple antennas using self-interference cancellation
US10878303B2 (en) 2012-03-09 2020-12-29 Neology, Inc. Switchable RFID tag
US10062025B2 (en) 2012-03-09 2018-08-28 Neology, Inc. Switchable RFID tag
US9667404B2 (en) 2012-06-07 2017-05-30 Telefonaktiebolaget Lm Ericsson (Publ) Duplexer-less transceiver and communication apparatus
US9793943B2 (en) 2012-06-07 2017-10-17 Telefonaktiebolaget Lm Ericsson (Publ) Duplexer-less transceiver and communication apparatus
WO2014075980A1 (en) * 2012-11-15 2014-05-22 Telefonaktiebolaget L M Ericsson (Publ) Transceiver front-end
EP2733855A1 (en) * 2012-11-15 2014-05-21 Telefonaktiebolaget L M Ericsson (publ) Transceiver front-end
US10084506B2 (en) 2012-11-15 2018-09-25 Telefonaktiebolaget Lm Ericsson (Publ) Transceiver front-end
US10348356B2 (en) 2013-03-14 2019-07-09 Telefonaktiebolaget Lm Ericsson (Publ) Transmitter receiver leakage reduction in a full duplex system without the use of a duplexer
US9923593B2 (en) 2013-03-14 2018-03-20 Telefonaktiebolaget Lm Ericsson (Publ) Transmitter receiver leakage reduction in a full duplex system without the use of a duplexer
US10027465B2 (en) 2013-04-26 2018-07-17 Telefonaktiebolaget Lm Ericsson Transceiver arrangement, communication device, method and computer program
US9871552B2 (en) 2013-04-30 2018-01-16 Telefonaktiebolaget Lm Ericsson (Publ) Transceiver arrangement, communication device, method and computer program
US9463816B2 (en) 2013-08-23 2016-10-11 Electro-Motive Diesel, Inc. Trainline communication network access point including filter
US9270335B2 (en) 2013-08-23 2016-02-23 Electro-Motive Diesel, Inc. Receive attenuation system for trainline communication networks
US9688295B2 (en) 2013-08-23 2017-06-27 Electro-Motive Diesel, Inc. Trainline network access point for parallel communication
US9260123B2 (en) 2013-08-23 2016-02-16 Electro-Motive Diesel, Inc. System and method for determining locomotive position in a consist
US9900044B2 (en) 2014-01-21 2018-02-20 Telefonaktiebolaget Lm Ericsson (Publ) Transceiver arrangement and communication device
US9560139B2 (en) 2014-04-11 2017-01-31 Electro-Motive Diesel, Inc. Train communication network
US9744979B2 (en) 2014-04-11 2017-08-29 Electro-Motive Diesel, Inc. Train communication network
WO2016016691A1 (en) * 2014-07-31 2016-02-04 Telefonaktiebolaget L M Ericsson (Publ) Duplexer system and associated digital correction for improved isolation
US10447337B2 (en) 2014-07-31 2019-10-15 Telefonaktiebolaget Lm Ericsson (Publ) Duplexer system and associated digital correction for improved isolation
US10200079B2 (en) 2014-10-29 2019-02-05 Telefonaktiebolaget Lm Ericsson (Publ) Transceiver arrangement and communication device
US10623048B2 (en) 2014-10-29 2020-04-14 Telefonaktiebolaget Lm Ericsson (Publ) Transceiver arrangement and communication device
US9711836B1 (en) 2015-10-30 2017-07-18 The United States of America as requested by the Secretary of the Air Force Tunable high isolation circulator
US11469821B2 (en) 2015-12-13 2022-10-11 GenXComm, Inc. Interference cancellation methods and apparatus
US10873877B2 (en) * 2016-07-16 2020-12-22 GenXComm, Inc. Interference cancellation methods and apparatus
US11330464B2 (en) * 2016-07-16 2022-05-10 GenXComm, Inc. Interference cancellation methods and apparatus
US20190253922A1 (en) * 2016-07-16 2019-08-15 GenXComm, Inc. Interference cancellation methods and apparatus
US10321357B1 (en) * 2016-07-16 2019-06-11 GenXComm, Inc. Interference cancellation methods and apparatus
US10680788B2 (en) 2016-12-22 2020-06-09 Intel Corporation Waveguide communication with increased link data rate
CN109997324B (zh) * 2016-12-22 2023-04-14 英特尔公司 一种全双工收发器、装置及系统
US10079668B2 (en) 2016-12-22 2018-09-18 Intel Corporation Waveguide communication with increased link data rate
CN109997324A (zh) * 2016-12-22 2019-07-09 英特尔公司 具有增加的链路数据速率的波导通信
WO2018118337A1 (en) * 2016-12-22 2018-06-28 Intel Corporation Waveguide communication with increased link data rate
US11356235B2 (en) * 2017-05-24 2022-06-07 The Board Of Trustees Of The University Of Illinois Self-interference cancellation for in-band full duplex single antenna communication systems
US11496178B2 (en) 2017-12-20 2022-11-08 Murata Manufacturing Co., Ltd. High-frequency module
US10804955B2 (en) * 2017-12-20 2020-10-13 Murata Manufacturing Co., Ltd. High-frequency module
US11777553B2 (en) 2017-12-20 2023-10-03 Murata Manufacturing Co., Ltd. High-frequency module
US11150409B2 (en) 2018-12-27 2021-10-19 GenXComm, Inc. Saw assisted facet etch dicing
US11309965B2 (en) 2019-07-15 2022-04-19 GenXComm, Inc. Efficiently combining multiple taps of an optical filter
US11215755B2 (en) 2019-09-19 2022-01-04 GenXComm, Inc. Low loss, polarization-independent, large bandwidth mode converter for edge coupling
US11539394B2 (en) 2019-10-29 2022-12-27 GenXComm, Inc. Self-interference mitigation in in-band full-duplex communication systems
US11796737B2 (en) 2020-08-10 2023-10-24 GenXComm, Inc. Co-manufacturing of silicon-on-insulator waveguides and silicon nitride waveguides for hybrid photonic integrated circuits
US11838056B2 (en) 2021-10-25 2023-12-05 GenXComm, Inc. Hybrid photonic integrated circuits for ultra-low phase noise signal generators

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